The violent merger of two sub-M\(_{\textrm {Ch}}\)  mass white dwarfs can also lead to ignition
and explosion, as discussed above. If the two white dwarfs are of sufficiently
different mass, as in the case presented by [1]}, low-velocity
oxygen may be the result of incomplete burning of some part of the less massive
white dwarf that is disrupted in the merger process. [1]} present a
simulation of a merger of two white dwarfs of mass 0.9 and 0.76 \(\textrm {M}_{\odot }\) ,
respectively, and show that as much as 0.5 \(\textrm {M}_{\odot }\)  of oxygen from the disrupted
secondary are left at \(v \mathrel {\unknown. {\hspace{1.0pt}\sim }}\) <\(\) 2000\(km\hspace{2.5pt}s\) -1\(. This is much more than we find in oursimulations of the nebular spectrum of SN\,2010lp, and it has a sphericaldistribution, which would not be compatible with the spectrum of SN\,2010lp, butit is at least one step in the required direction. Compared to their model,SN\,2010lp produced much less oxygen, and it ejected it in two blobs. They alsoused a larger value of the reddening than we find here, and therefore had to usea 0.9\,\textrm {M}_{\odot }\ white dwarf as the primary of the system in order to synthesizeenough \) 56\(Ni\ (0.18\,\textrm {M}_{\odot }). With the smaller reddening determined here theamount of \) 56\(Ni\ necessary to fit the light curve of SN\,2010lp would be less.We estimate here that \) 0.08\(\,\textrm {M}_{\odot }of \) 56\(Ni\ were sufficient toenergise the nebular spectrum of SN\,2010lp, while for SN\,1991bg\cite {mazz91bgneb} estimated 0.06\,\textrm {M}_{\odot }. Some merger scenario with slightlydifferent masses and mass ratios might produce the required mass anddistribution of oxygen.\) A third possibility is that the two blobs mark part of the material that
survives the explosion following the impact (collision) of two sub-M\(_{\textrm {Ch}}\)  white
dwarfs, as in the models of [3]}. Although the original model of
white dwarfs collision envisages the creation of two central blobs of \(^{56}\) Ni  it
may not be excluded that some particular configuration, or range of white dwarf
masses, may lead to an outcome similar to what is diagnosed in SN 2010lp. The
question in this case might be, what would then set these inner regions into
expansion?
